Initiation of Lightning in Thunderclouds

摘要

The maximum electric fields typically measured in thunderclouds are reviewed with a view toward lightning initiation mechanism. Initial breakdown processes in both cloud-to-ground and cloud discharges are considered, and characteristics of associated electric and magnetic field pulses are given. Narrow bipolar pulses attributed to the so-called compact intracloud discharges are characterized. Proposed mechanisms of lightning initiation in thunderclouds are presented and discussed.